JPH0388895A - Lubricating oil composition - Google Patents

Abstract

PURPOSE:To provide the title composition excellent in viscosity index-improving effect, wear resistance and shear stability, thus to be used as internal-external combustion engine oil, hydraulic fluid, refrigeration machine oil, etc., comprising a low-viscosity oil as dispersion medium and, as disperse phase, a high-viscosity oil incompatible with the low-viscosity oil. CONSTITUTION:The objective composition comprising (A) a low-viscosity oil as dispersion medium, consisting of silicone oil, olefin oligomer, mineral oil, organic acid ester, phosphoric ester, polyalkylene glycol, alkylbenzene or derivative thereof (esp. pref. with a kinematic viscosity of 3-30mm<2>/s at 100 deg.C) and (B) a high-viscosity oil as disperse phase, incompatible with the component A, such as silicone oil, fluorinated oil, olefin oligomer, short chain polymethacrylate or polyalkylene glycol (esp. pref. with a kinematic viscosity of 30-30000mm<2>/s at 100 deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to internal combustion engine oils, external combustion engine oils, hydraulic oils, refrigeration oils, compressor oils, gear oils, and lubricating oil compositions for various machines.

[Conventional technology]

Conventionally, lubricating oil compositions for internal combustion engine oil, external combustion engine oil, hydraulic oil, refrigeration oil, compressor oil, gear oil, and various machines have been made of mineral oil,
Using synthetic oils such as silicone oil, olefin oligomers, organic acid esters, and alkylbenzenes as base oils,
In order to improve its physical properties, it is manufactured by adding viscosity index improvers, anti-wear agents, etc. Although several types of base oils may be used as a mixture, base oils that are compatible with each other are used as a mixture.

However, although the addition of additives is useful in improving lubricating oil & lubricant acid performance, for example, when using viscosity index improvers, the viscosity decreases due to shearing of the polymer during use. Furthermore, there is a problem in that the addition of anti-wear agents increases costs.

[Problem to be solved by the invention]

The present invention has unexpectedly discovered that by dispersing a high viscosity oil in a low viscosity oil, the viscosity index improving effect, abrasion resistance, and shear stability can be improved. As a result, the present invention can omit or reduce the addition of viscosity index improvers and anti-wear agents, prevent a decrease in the viscosity of the oil used, and provide a long-life lubricant assembly! The challenge is to provide goods.

[Means to solve the problem]

The lubricating oil composition of the present invention is characterized by comprising a low-viscosity oil as a dispersion medium and a high-viscosity oil as a dispersoid that is substantially incompatible with the dispersion medium.

Further, the lubricant composition is characterized in that a dispersant is added to stably disperse high viscosity oil in low viscosity oil.

As the low viscosity oil, silicone oil, olefin oligomer, mineral oil, organic acid ester, phosphoric acid ester, polyalkylene glycol, alkylbenzene and its derivatives, etc. can be used.

The kinematic viscosity of the low viscosity oil used as the dispersion medium is 1 at 100°C.
o+m"/s to 100 mm"/s, particularly preferably low viscosity oils having a kinematic viscosity of 3 an"/s to 30+*s"/s are used.

First, as a silicone oil (hereinafter referred to as blank space), <herein, R is a group selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group, and a cyanoalkyl group, and n is O or 1 or more. (integer).

In addition, the olefin oligomer that can be used in the present invention has 2 to 14 carbon atoms, preferably 4 to 14 carbon atoms.
Any one homopolymer selected from olefinic hydrocarbons with or without branching in the range of 12 or 2
Preferred olefins are those obtained by copolymerization of more than one species, and are selected from products with an average molecular weight of 100 to about 2000, preferably 200 to about 1000, and those with unsaturated bonds removed by hydrogenation are particularly preferred. Examples of the oligomer include polybutene, α-olefin oligomer, and ethylene/α-olefin oligomer. Preferably, the polybutene is one obtained by copolymerizing a monomer mixture of butene-12 and butene-2, with isobutene as the main component, and α-olefin oligomers include those obtained by thermal decomposition of hydrocarbons or lower olefins. α having 6 to I2 carbon atoms obtained by trimerization to hexamerization of
- olefin mixture, e.g. 25% by weight of hexene-1
~50% by weight, 30% to 40% by weight of octene-■
A copolymerized mixture of 25% to 40% by weight of decene-1 and decene-1 can be used. Also suitable are oligomers obtained from single monomers such as decene. Furthermore, as ethylene/α-olefin oligomer,
40% to 90% by weight of ethylene, α-olefin 1
For example, a mixture of monomers containing propylene in a proportion of 10% to 60% by weight and polymerization can be used.

These olefin oligomers include argonium chloride,
It can be produced using a Friedel-Crafts type catalyst such as boron fluoride, a Ziegler catalyst, and an oxide catalyst such as chromium oxide. Hydrogenation of olefin oligomers can also be carried out by removing the catalyst from the reaction product and then bringing it into contact with a hydrogenation catalyst such as nickel-molybdenum/aluminium oxide under heat and pressure.

Alkylbenzenes can also be included as one of the low viscosity oils of the present invention. This is mainly of the alkylbenzene type, and is mainly a dialkylated aromatic hydrocarbon that is produced as a by-product when making detergent raw materials by alkylating aromatic hydrocarbons such as benzene and toluene through a free-sol Tarafluor reaction. Contains oil. The alkyl group includes either a straight chain or a branched alkyl group.

Mineral oils are hydrocarbon oil fractions with lubricating viscosity, such as raffinate obtained by extracting vacuum distillation distillate oil with a solvent such as phenol, furfural, or N-methylpyrrolidone. Hydrocarbon distillate oil obtained after solvent deasphalting treatment and, if necessary, further hydrorefining to improve hue and remove unstable substances, or this hydrocarbon distillate oil and solvent. Mixtures with residual oils from extraction, solvent dewaxing and solvent deasphalting processes can be used. Also, contact sharp edge treatment may be performed instead of solvent sharp edge treatment. These refined mineral oils may be hydrocarbon oils such as mineral oils, paraffinic oils, naphthenic oils, etc. alone, or a mixture of these hydrocarbon oils.

Next, as one of the organic acid esters, there is one obtained by reacting an aliphatic dibasic acid having 4 to 14 carbon atoms with an aliphatic alcohol having 4 to 14 carbon atoms.

Dibasic acids that can be used for its synthesis include, for example, succinic acid, glutaric acid, adipic acid, piperic acid,
speric acid, azelaic acid, sebacic acid, undecanol, dodecanoic acid, brassylic acid, and tetradecanoic acid, preferably adipic acid, azelaic acid, sebacic acid,
Among these, adipic acid and sebacic acid are particularly preferred.

Examples of aliphatic alcohols include n-butanol, isobutanol, n-amyl alcohol, isoamyl alcohol, n-hexanol, 2-ethylbutanol, cyclohexanol, n-heptatool, isoheptatool, methylcyclohexanol, n-octa- Tool, dimethylhexanol, 2-ethylhexanol, 2.4
．． 4 trimethylpentanol, isooctatool, 3.
Examples include 5.5-trimethylhexanol, isononanol, isodecanol, isoundecanol, 2-butyloctatool, tridecanol and isote, tradecanol, and 2-ethylhexanol, isodecanol, and tridecanol are particularly preferred.

The synthesis of diesters from dibasic acids and alcohols can be carried out by conventional methods, such as dehydration condensation under acidic catalysis. The diesters obtained in this way are, for example, di(1-ethylpropyl)adipate, di(3-methylbutyl)adipate, di(l,3-dimethylbutyl)adipate, di(2-ethylbutyl)
Adipate, di(2-ethylhexyl)adipate,
Di(isooctyl)adipate, Di(isononyl)
Adipate, di(3,5,5 trimethylhexyl)adipate, di(isodecyl)adipate, di(undecyl)adipate, di(tridecyl>adipate,
Di(isotetradecyl)adipate, Di(2,2,
4-Trimethylpentyl〉Adipate, G [Mixed (2
-ethylhexyl, isononyl)] adipate, di(
1-ethylpropyl) azelate, di(2-ethylbutyl) azelate, di(2-ethylhexyl) azelate, di(isooctyl) azelate, di<isononyl) azelate, di(3,5,51-limethylhexyl) azelate, di( Isodecyl> azelate, di(tridecyl) azelate, di [mixed (2-ethylhexyl, isononyl)] azelate, di [mixed (2-ethylhexyl, isononyl)]
-ethylhexyl, decyl)) azelate, di[mixed (2-ethylhexyl, isodecyl)] azelate, di[mixed (2-ethylhexyl, 2-propylheptyl)] azelate, di[mixed (2-ethylhexyl, decyl)] azelate, di(n-butyl) sebacate,
Di(isobutyl) sebacate, di(1-ethylpropyl) sebacate, di(3-methylbutyl) sebacate, di(l,3-dimethylbutyl) sebacate, di(2-ethylbutyl) sebacate, di(2-ethylhexyl) sebacate, Di(2-(2-ethylbutoxy)ethylbutanol, Di(2,2,4-trimethylpentyl)sebacate, Di(isononyl)sebacate,
G (3,5゜5 trimethylhexyl> sebacate, G (isodecyl) Sebacate, G (isoundecyl)
Sebacate, di(tridecyl) sebacate, di(isotetradecyl) sebacate, di[mixed (2-ethylhexyl, isononyl)] sebacate, di(2-ethylhexyl) glutarate, di(isoundecyl) glutarate and di(isotetradecyl) glutarate etc.

Another type of organic acid ester is neopentyl polyol ester.

Neopentyl polyol ester is produced by synthesis of neopentyl polyol having 5 to 9 carbon atoms and mtrx having 4 to 18 carbon atoms. In the present invention, neopentyl polyol is a polyhydric alcohol having a neopentyl group, For example, 2,2-dimethylpropane-1,3-
Diol (i.e. neopentyl glycol), 2-ethyl-2-butyl-propane-1,3-diol, 2.2
-diethylpropane-1,3-diol, 2,2-dibutylpropane-1,3-diol, 2-methyl-2-propylpropane-1,3-diol, 2-ethyl-2-
Butylpropane-1,3-diol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, preferably neopentyl glycol, 2-methyl-2-propylpropane-1,3-
diol, trimethylolpropane, and pentaerythritol, and particularly preferred are neopentyl glycol, trimethylolpropane, and pentaerythritol. Further, organic acids include, for example, n-butanoic acid, isobutanoic acid, n-pentanoic acid, isopentanoic acid, n-hexanoic acid,
2-ethylbutanoic acid, cyclohexanoic acid, n-hebutanoic acid, isohbutanoic acid, methylcyclohexanoic acid, n-octanoic acid, dimethylhexanoic acid, 2-ethylhexanoic acid, 2゜4.4-)limethylbenconic acid, isooctanoic acid , 3.5.5-trimethylhexanoic acid, n-nonanoic acid,
Isononanoic acid, isodecanoic acid, isoundecanoic acid, 2-
These are butyloctanoic acid, tridecanoic acid, tetradecanoic acid, hexadecanoic acid and octadecanoic acid, preferably hebutanoic acid, n-octanoic acid and 2-ethylhexanoic acid.

The synthesis of a neopentyl polyol ester from an organic acid and a neopentyl polyol can be carried out by a conventional method, for example, a method of dehydration condensation under an acidic catalyst.

For example, as neopentyl polyol ester, neopentyl is NPC, trimethylolpropane GT
MP and pentaerythritol are abbreviated as PE. ')
, NPC G (heptanoate), NPC G (
2-ethylbutyrate), NPC・G(cyclohexanony)), NPC・G(heptanoate), N
PC・G (isoheptanoate), NPC・G (octylate), NPC・G (2-ethylhexanony)), NPC・G (isooctanoate), NPC
・G (isononylate), NPC・G (isodecaneate), NPC・G (mixed <hexanoate, heptanoate)), NPC・G (mixture (hexanoate, octanoate)), NPC・G (mixture (hexanoate, nonylate)), NPC・G (mixed)
Heptanoate.

Okukunoe))), NPC-G (mixed (heptanoate, nonylate)), NPC-G (mixed (heptanoate, isooctanoate)), NPC-G (
Mixture (heptanoate, isononylate)), NPC
・G (mixture (isooctanoate, isononylate)
), NPC・G (mixed (butanoate, tridecanoic acid)) ), NPG・G (mixed (butanoate, tridecanoic acid))
Tetrazocanny))), NPG-G C mixture (butanoate).

hexadecanoate)), NPC-G (mixed (butanoate, octadecanoate)), NPC-G (mixed (hexanoate, isooctanoate, isononanoic acid))), NPG-G (mixed (hexanoate, iso-octanoate)) ate, isodecanate) l, N
PC・G (mixed (heptanoate, isooctanoate, isononylate)), NPC・G (mixed (heptanoate)).

isooctanoate, isodecanate)), NPC・
G (mixed (octanoate, isononylate, isodecanoate))), TMP/Tree (pentanoate)
, TMP tri (hexanoate), TMP tri (heptanoate), TMP tri (octanoate), TMP tri (nonylate), TMP tri
Tory (isopentanoate), TMP Tory (2-
ethyl butanoic acid)), TMP tri(isopentanoate'), TMP tri(isooctanoate)
, TMP tri(2-ethylhexanoate), TM
P-tree (isononylate) + TMP-tree (isodecanoate), TMP-tree [mixture (butyrate, octadecanoate)], TMP-tree [mixture (butyrate, octadecanoate)]
hexanoate, hexadecanoate)), TMP/Tree [mixture (heptanoate, tridecanoate))
, TMP-tree [mixture (octanoate, decanoate)], TMP-tree [mixture (octanoate, nonylate)), TMP-tree [mixture (butyrate, heptanoate, octadecanoate))], TMP-tree [mixture (pentanoate, heptanoate, tridecanoate)), TMP/Tree [Imiai (hexanoate, heptanoate, octanoate)],
PE Tetra (Pentanoate), PE Tetra (Hexanoate), PE Tetra (Isopentanoate),
PE Tetra (2-ethylbutyrate), PE Tetra (isoheptanoate), PE Tetra (isooctanoate), PE Tetra (2-ethylhexanony)
, PE tetra(isononylate) and PE and carbon number 4
-8 linear or branched carboxylic acids, etc.

Also, neopentyl polyols other than NPC, TMP and PE, i.e. 2-methyl-2-propylpropane-1,3
-diol, 2,2-diethylpropanediol, trimethylolethane, and trimethylolhexane, and polyol esters of the above-mentioned organic acids alone or in combination.

Phosphate esters include tricresyl phosphate,
Tritolyl phosphate, tri(2-ethylhexyl) phosphate, alkylphenyl phosphate, alkylphenyl phenyl phosphate, etc. can be used.

The polyalkylene glycol is a ring-opening polymer or a ring-opening copolymer of a linear or branched alkylene oxide in which the alkylene group has 2 to 5 carbon atoms, preferably 2 to 3 carbon atoms. Examples of alkylene oxide include ethylene oxide, propylene oxide, butylene oxide,
or a mixture thereof, preferably propylene oxide, preferably polyethylene glycol, polypropylene glycol, molecular weight range 1
00 to 2000, preferably 200 to 1000.

Next, the dispersoid dispersed in the low viscosity oil will be explained.

As the highly viscous oil which is a dispersoid, silicone oil, fluorinated oil, olefin oligomer, short chain polymethacrylate, polyalkylene glycol, etc. may be used.

The kinematic viscosity of these high viscosity oils is 100°C at 100°C.
No. 3 to 100. 000 sn"/s, particularly preferably kinematic viscosity of 30 sn"/s to 30.00 sn"/s. OO05m
It is advisable to use a high viscosity oil of 1/s.

The silicone oil is represented by (where R is a group selected from the group consisting of a monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group, and a cyanoalkyl group, and n is O or an integer of 1 or more). The average molecular weight is in the range of 500 to 200°,000.

The fluorinated oil is polychlorotrifluoroethylene (CFi-CFCI) represented by the following formula (where n is 4 to 18) (molecular weight 500 to 2,000, kinematic viscosity at 100°C 10
sn"/s ~1,000sn"/s) (in the formula, n is 10-60) Molecular weight 2.000-10,000.100°C
Those having a kinematic viscosity of 10 mg+"/s to 50+ m"/s can be used.

The α-olefin oligomer has 35 to 3 carbon atoms,
It is obtained by copolymerization of any type of homopolymer or two or more types selected from olefinic hydrocarbons with or without branches in the range of 500, preferably 50 to 700, and has an average molecular N500 to so, ooo, preferably from 700 to 10,000, but those from which unsaturated bonds have been removed by hydrogenation are particularly preferred. Preferred olefin oligomers include, for example, polybutene, α-olefin oligomers, ethylene α
-Olefin oligomers, etc.

The kinematic viscosity at 100°C is 10+a+s”/s~10,
000 mm''/s can be used.

In addition, polymethacrylate has a kinematic viscosity of 5 (1+s"/ s~100,
OOO+uw”/s can be used.

The polyalkylene glycol is a ring-opening polymer or a ring-opening copolymer of a linear or branched alkylene oxide having an alkylene group having 2 to 5 carbon atoms, preferably 2 to 3 carbon atoms. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, or mixtures thereof, preferably propylene oxide, and preferably polyethylene glycol and polypropylene glycol having a molecular weight of 500 to 20,000.

In the lubricating oil composition of the present invention, it is necessary that the low viscosity oil that is the dispersion medium and the high viscosity oil that is the dispersoid have no compatibility. In the combination, it is necessary to make the combination non-compatible.

First, when silicone oil is used as the low viscosity oil, all of the dispersoids other than the high viscosity silicone oil are insoluble and can be used as the lubricating oil composition of the present invention. Particularly preferred is the case where polyethylene glycol or polypropylene glycol is used as the dispersoid.

Furthermore, when an olefin oligomer is used as a dispersion medium, silicone oil, short-chain polymethacrylate, polyethylene glycol, or polypropylene glycol may be used as the incompatible dispersoid.

When mineral oil is used as the dispersion medium, silicone oil, short chain polymethacrylate, polyethylene glycol, or polypropylene glycol may be used as the dispersoid.

Furthermore, when an organic acid ester is used as a dispersion medium, silicone oil is preferably used as a dispersoid.

Furthermore, when a phosphoric acid ester is used as a dispersion medium, silicone oil or an olefin oligomer may be used as a dispersoid.

Furthermore, when polyethylene glycol or polypropylene glycol is used as a dispersion medium, silicone oil or olefin oligomer may be used as a dispersoid.

Furthermore, in the present invention, the kinematic viscosity ratio at 100°C of low viscosity oil and high viscosity oil is 2 to 2 when the kinematic viscosity of low viscosity oil is 1.
The range is preferably 100,000, especially 5 to 3,000.
The lubricating oil composition of the present invention is preferably in the range of 0.0 The lubricating oil composition of the present invention is constituted by appropriately selecting such a kinematic viscosity ratio from the above-mentioned dispersion medium and dispersoid, and the kinematic viscosity ratio is If it is less than 2, the viscosity of the dispersion medium and dispersoid will be close, and the viscosity of high viscosity oil will be so low that its characteristics will not be clear compared to the dispersion medium alone, and if it is more than 100.000, the oil will be in a solid state. Dispersoids, which are not preferred, may be used in an amount of 0.5% to 50% by weight, preferably 1% to 30% by weight, based on the dispersion medium.

In order to disperse the dispersoid in the dispersion medium, it is preferable to mix the two liquid components using a mixer or a roll mill. is dispersed during use, so lubricating oil &
Although the dispersion medium and the dispersoid may be separated in the animal, it is preferable to add a dispersant to the lubricating oil & lubricant acid compound of the present invention to uniformly disperse them.

The dispersant is not particularly limited, but may be appropriately selected from low-molecular dispersants and polymer dispersants.

Specific examples of low-molecular dispersants include aliphatic or aromatic carboxylic acid metal salts or their esters, sulfate ester type metal salts, sulfonate ester type metal salts, phosphate ester type metal salts, and quaternary ammonium salts. etc., nonionic surfactants such as polyoxyethylene, polyhydric alcohol, and alkylolamide, and polymeric dispersants such as lipophilic polar substances such as polyester, polyamide, polyamine, and derivatives thereof, and alkenylsuccinic acid. Imide, alkenylbenzylamine, petroleum resin (indencoumarone resin), various rosins, derivatives thereof, etc. can be used. The addition ratio of the dispersant is 0.05% by weight to 20% by weight.
% by weight can be used, preferably from 0.1% to 10% by weight.

The lubricating oil composition of the present invention may optionally contain a metal detergent (
At least one additive such as magnesium sulfonate, etc.), ashless detergent and dispersant (alkenyl succinimide, etc.), antioxidant (phenol, zinc thiophosphate, etc.), antifoaming agent (silicon, etc.) is added. In particular, metal detergents can contain 0.1% to 5.0% by weight, ashless detergent dispersants have a content of 0.1% to 10.0% by weight, and antioxidants have a content of 0.1% to 5.0% by weight.
1% by weight to 1.5% by weight, antifoaming agent from 0.001% by weight
The content is preferably 0.01% by weight.

[Effect]

The lubricating oil composition of the present invention is prepared by dispersing a high viscosity oil in a low viscosity oil, and by first dispersing particulate liquid high viscosity oil in the low viscosity oil, It is thought that the liquid high viscosity oil swells at high temperatures and its volume fraction in the lubricating oil increases, resulting in an increase in viscosity and an improvement in the viscosity index (viscosity index improving property).
In addition, high viscosity particles support the load on the friction plane and maintain an oil film, reducing friction and preventing wear by preventing metal-to-metal contact (improving wear resistance). Compared to commonly used viscosity index improvers, molecules are less likely to break due to shearing.
It was discovered that there was no decrease in viscosity (shear stability).

Therefore, the lubricating oil composition of the present invention is particularly suitable for use as a lubricating oil & I It is something that can be done with great pride.

[Example 1] Dispersion medium; Mineral oil; 100 neutral, viscosity 4.3 am"/
5 (100°C) Dispersoid; Polypropylene glycol (trade name LB-3000, Sanyo Kakai special product, viscosity 90+
ms”/s (100°C) Dispersant: Using alkenyl succinate ester (trade name Lubrizol 936, manufactured by Lubrizil), 1.0% by weight of dispersoid was added to mineral oil at 5°0.
%, 7.5% by weight, and 10.0% by weight, respectively, and a composition uniformly containing 3.0% by weight of a dispersant was mixed using a mixer to obtain a lubricating oil composition of the present invention.

The kinematic viscosity and viscosity index of each of the lubricating oil compositions of the present invention were measured using 1IsK2283.

The results are shown as line A in FIG. Note that the numbers on line A indicate the content of dispersoids (% by weight).

As a comparison, the same mineral oil as above contained 7.0% by weight of polymethacrylate (trade name, PLX-1019, manufactured by Nippon Acrylic), which is a viscosity index improver, and the results of measuring the kinematic viscosity and viscosity index were the same. It is shown by line B in FIG.

Similarly, the viscosity indexes of mineral oils having various kinematic viscosities of 100 neutral mineral oil mixed with ply stock were measured, and the results are shown as cl in FIG.

According to this, it can be seen that the lubricating oil composition of the present invention exhibits a higher viscosity index improving effect compared to those to which a viscosity index improver is added and those containing mineral oil alone.

[Example 2] (Abrasion resistance test) 10% by weight of the polypropylene glycol used in Example 1 as a dispersant and 3% by weight of the succinic acid ester used in Example 1 as a dispersant were added to 100 neutral mineral oil. A lubricating oil composition of the present invention was prepared by dispersing the mixture using a mixer.

As a comparison of the present invention, mineral oil (100 Neutral+Pritestonk) and additive oil for gear oil containing 7% by weight of polymethacrylate (PLX-1019, manufactured by Nippon Acrylic ■) in mineral oil 100 Neutral were used. Both oils have a velocity of 6.3 mm”/s to 6.7 m at 100°C.
m"/s.A comparative test for abrasion resistance was carried out using a shell four-ball abrasion resistance tester.
According to EMD4172, the test conditions were 60Orpm,
The test was carried out under a load of 15 kg, a temperature of 60° C., and a time of 30 minutes), and the relationship between the load (kg) and the wear scar radius (opening) was determined.

The results are shown by the dashed line in FIG.

In addition, the mark ○ on the broken line indicates the case of the lubricating oil composition of the present invention.
The marks are the measurement results for gear oil with viscosity index improver added. According to this, it can be seen that the lubricating oil of the present invention has excellent wear resistance compared to the oil containing a viscosity index improver for gear oil.

Furthermore, each of the lubricating oil composition of the present invention, the gear oil viscosity index improver-added oil, and mineral oil alone contained 0.5% by weight of zinc dialkyldithiophosphate, which is an anti-wear agent. A sex test was conducted. This result is shown in FIG. 2 as a solid line.

In addition, the ○ mark on the solid line indicates the case of the lubricating oil composition of the present invention,
Also, the mark indicates the case of mineral oil with addition of viscosity index improver for gear oil, and the mark indicates the case of mineral oil alone.

According to this, it can be seen that the lubricating oil &lI of the present invention has excellent wear resistance compared to the viscosity index improver-added oil for gear oil. Furthermore, the wear resistance can be improved by adding an anti-wear agent, and it is clear that this effect is particularly remarkable compared to oils containing viscosity index improvers for gear oils and mineral oils.

[Example 3] (Shear stability test) The lubricating oil composition of the present invention prepared in Example 2 and the viscosity index improver-added oil for gear oil (polymethacrylate 7% by weight)
All four types of oil are 1.
6°3 ms+"/s ~6,7 am" at 00'C
For each case alone, lubricant shear stability tests were conducted in accordance with Petroleum Institute Standard JPI-6S-29-88 with a sample irradiation time of 30 minutes. FIG. 3 shows the relationship between shearing time (minutes) and viscosity change rate, and FIG. 4 shows the relationship between shearing time (minutes) and viscosity index.

In the figure, the case of the lubricating oil composition of the present invention is marked with ○, the case of gear oil with viscosity index improver added is marked with Δ, the case of engine oil with viscosity index improver added is marked, and the case of mineral oil alone is marked. is indicated with a ・mark.

This shows that the lubricating oil composition of the present invention exhibits superior shear stability compared to oils containing a viscosity index improver.

〔Effect of the invention〕

The lubricating oil composition of the present invention consists of a low-viscosity oil as a dispersion medium, a high-viscosity oil as a dispersoid that is substantially incompatible with the dispersion medium, and a dispersant further contained as necessary. It has a high viscosity index improvement effect, has excellent abrasion resistance, and also exhibits excellent shear stability.
In particular, it is excellent for internal combustion engine oil, external combustion engine oil, hydraulic oil, refrigerating machine oil, compressor oil, gear oil, and lubricating oil for various machines.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the viscosity index improving property of the lubricating oil composition of the present invention, FIG. 2 is a diagram for explaining the wear resistance of the lubricating oil composition of the present invention, FIG. FIG. 4 is a diagram for explaining the stability of lubricating oil All compound acid of the present invention. Applicant: Toenen Co., Ltd.

Claims (2)

[Claims] (1) A lubricating oil composition comprising a low-viscosity oil as a dispersion medium and a high-viscosity oil as a dispersoid that is substantially incompatible with the dispersion medium. (2) The lubricating oil composition according to claim 1, wherein a dispersant is added.